After a six-year period as a Financial Post columnist from 1985 to 1991, Coyne joined The Globe and Mail's editorial board.[6] There, Coyne won two consecutive National Newspaper Awards for his work.[9] He had a regular column in the Globe between 1994 and 1996, when he joined Southam News (later CanWest News Service) as a nationally syndicated columnist.[7]

Coyne became a columnist with the National Post – the successor to the Financial Post – when it launched in 1988.[10] Coyne left the Post in 2007 to work at Maclean's.[10]

Coyne left Maclean's in 2011 to return to the Post as a columnist.[10] In December 2014, he was appointed to the position of Editor, Editorials and Comment.[11] After years of writing a weekly Saturday column, Coyne's contribution was absent from the edition published just prior to the 2015 Canadian federal election, because the column he wanted to submit called for a vote against the Conservative Party of Canada while the Post's editorial board had endorsed the Conservatives.[12][10] While Coyne was the head of the editorial board, the decision to endorse the Conservatives was made the newspaper's publisher Paul Godfrey.[10] On election day, Coyne announced that as a result of the paper refusing to run his election column, he was resigning as the Post's editorial page and comment editor but would remain as a columnist.[10][13]